1. Field of the Invention
The present invention relates to a particle therapy system, and more particularly to a particle therapy system for irradiating a charged particle beam, such as a proton or carbon ion beam, to a diseased part for treatment.
2. Description of the Related Art
There is known a therapy method of irradiating a charged particle beam, such as a proton beam, to a diseased part, e.g., a cancer, in the body of a patient. A large-scaled one of therapy systems used for practicing such a therapy method conventionally comprises a charged particle beam generator, a beam transport system, and a plurality of treatment rooms. The charged particle beam accelerated by the charged particle beam generator reaches an irradiation apparatus in each treatment room through the beam transport system, and it is irradiated to the diseased part in the patient body from a nozzle of the irradiation apparatus. For that purpose, the beam transport system comprises a first beam transport system as one common system and a plurality of beam transport systems branched from the one first beam transport system and led to the respective irradiation apparatuses in the plurality of treatment rooms. At a position where each of the branched beam transport systems is branched, a switching magnet is disposed to bend the charged particle beam from the first beam transport system to be introduced to the corresponding branched beam transport system (see, e.g., Patent Reference 1: JP,A 11-501232 (pp. 12-13, FIGS. 1 and 2).